Telephone system.



H. P. CLAUSEN 6: C. LJGOO DRUM.

TELEPHONE SYSTEM. APPLICATION FILED 05c. 29. 1916.

III I n u I Illll I III I v Char/a9 L. fiaodlum. I w

UNITED STATES PATENT @FFIGE.

HENRY P. CLAUSEN, OF MOUNT VERNON, AND CHARLES L. GOODRUM, OF NEW YORK, N. Y., ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEVI YORK, N. Y.,.A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed December 29, 1916.

1/ b all whom. 2'25 may concern:

lie. it known that we, HENRY P. CLAUSEN and CHARLES L. GoonnUM, citizens of the United States, residing at Mount Vernon, in the county of 'estchester and State of New York. and at New York, in the county of New York and State of New York, respectively, have invented certain new and useful Improvements in Telephone Systems, of which the following a full, clear, concise, and exact description.

This invention relates to telephone switching systems of a type employing automatic switching apparatus in the completion of connections and has for its object in general, the provision of apparatus and circuits for facilitating the rapid limiting over a large .numher of contacts in the making of connections.

In accordance with the general features of this invention. the terminals over which limiting is to take place a re divided into two general groups. and means are provided for automatically transi"erring the hunting movement ot the brushes from one group to the other in case all tern'iinals in the first group to which the brushes have been moved are busy. The apparatus and circuits are so arranged that aplurality of brushes are adapted to sin'uilt'ineously engage and test separate terminals in the time required to movethe brushes between adjacent terminals.

Specifically. the terminals are divided into two groups. each group comprising two subgroups. and the switch is provided with a set of brushes for each sub-group which are adapted in the movement of the switch to sin'iultaneously engage contacts of their respective sub-groups. Switching mechanism operating in conjunction with the brush moving mechanism is adapted to successively include each set of brushes in the testing circuit for each step or movement of said brushes. Provision is also made whereby, when a set of brushes has been moved into operative relation with one group of terminals by directive impulses, the switch will operate automatically to move said brushes into operative relation with the-other group of terminals in case all of the terminals of the first group are busy. This is aceomplished through the agency of a test brush Specification of Letters Patent.

Patented Jan. L 1918.

Serial No. 139,525.

carried by the switch operating in conjunction with the driving mechanism of said switch to advance the brush carrying shaft through a distance less than its normal movement in response to an impulse.

More specifically this invention contemplates the combination, in a selective switch, of means by which groups of trunks may be tested in one operation, and means by which a plurality of separate trunks may be tested at a higher speed than the speed of the switch when thespecd of the switch is defined as the number of contacts a brush passes over in a given time.

The drawing represents diagrammatically a calling snbscribe'rs sub-station connected through a line switch (indicated by the broken lines but not shown) to a selector switch embodying this invention.

S represents a calling subscribers substation; the brushes 71 7F and 7)" represent brushes of a line switch: and SS represents a selector switch Let it be assumed that the subscriber at sub-station F4. in ,making a call. IOIHOVOH his receiver from i t's'hook, and in a well-known manner the brushes b 5 and 7) of theline switch are extended to tern'iinals f 25-. f of the selector switch SS. A circuit is thereupon established from ground. battery, right-hand winding of relay Lll. first position contactand sideswitch wiper \V. the terminal 5. the brush 7/. the telephone line and apparatus of the subscribers sub-station S. the brush 72 the terminal I. the side-switch wiper 7?. its first position contact, the left-hand winding of line relay LR to ground. The line relay attracts its armature and establishes a circuit. from ground. the armature and alternate contact of relay LR, the winding of the first slow relayl to battery and ground.

It should be noted that: the system herein disclosed is one in which the idle condition of a selective switch is denoted by a ground potential on the terminals of the circuits, and in the case illnstrated,the idle condition of the selector was denoted. before its seizure, by a ground on the terminal 25 extended from ground. the armature and normal contact of relay LR. the armature and normal contact of relay 1. first position contactand side-switch wiper N to terminal 6 Upon the seizure of this. selector switch the and 1.

Relay 1 now attracts its armature and prepares a circuit for the primary movement of the selector switch.

v When the subscriber at sub-station S operates his impulse-sender D, a series of interruptions in the line circuit are caused thereby, and result in the intermittent delinerization of relay LR, whereby its armature is caused to vibrate rapidly. Upon the first retraction of this armature a circuit is es tablished from ground, armature and normal contact of relay LR, the armature and alternate contactot relay 1 to a point where the circuit divides, extending in one direction through the-primary magnet PM to battery and ground, and intheother direction through the winding of relay 2 to battery and ground. Relay 2 being slow to release is not affected by the intermittent interruptions of this circuit and retains its armatures in their attracted positions until the impulse-sender D has completed its full movement. The primary magnet Pill, however, is responsive to the intermittent deenerization of relay LR and causes its armature to rapidly vibrate, whereby the pawl "P is brought into engagement with the ratchet member 3, and causes the rotation of the shaft 4. g

It should be noted at this point that the armature of the magnet PM is so adjusted that the pawl -P will engage every other tooth of the ratchet member 3, and thereby rotate the shaft two steps in each movement. It should also be noted that the brush 5 secured to the uppermost end of the shaft 4 passes over two of the terminals 6 at each.

step, and comes to reston a terminal 6 to which a circuit 7 in connected.

Upon the completion ofthis movement by the impulse transmitter D, and the receipt ofthe last impulse, the armature of relay LR is held attracted for a comparatively long period of time and the circuit over which PM were energized is opened at ruit was established from ground. the coutart and left-hand armature of relay E2, wind- {ing of escape magnet 16, battery and ground, through which the escape magnet was encrgizcd and held energized until a fter the impulse transmitter D completed full movement. New, upon the deem ization ot'ie lay '2, this circuit is opened and another citordinary movement.

cuit is established from ground, battery. winding of magnet PM, the winding of magnet 8, normal contact and right-hand armature of relay 2, the side-switch wiper l and its first position contact, the brush 5, the terminal 6, circuit conductor 7,through the off-normal contacts of the switches, the trunks to which terminate in subgroups G and G, in series, to ground, if, as we may assume, all of these switches are busy. Through this circuit then, and before the escape magnet,.due to its slow release feature, can retract its armature, the magnets 8 and PM are energized. Magnet 8 attracts its armature and through the extension 9 puts a stop in the path of the armature of magnet PM, whereby the pawl P is allowed to turn the shaft only half as far as in its sets of brushes B and B are brought into In such a manner the.

association with the subgroups of terminals Gr and G.

The escape magnet 16 retracts its armatures, and in sodoing steps the side-switch wipers into the second position. Thereupon a circuit is established from ground, sideswitch wiper W, its second posltloncontaet,

the normal contact and innermost lower ari which are encountered by the brush set 13 lead to a selector switch which is idle, ground, by which this idle condition is 'denoted, will be extended from the test terminal of such set of terminals, through the test brush of the set E the normal contact and innermost upper armature of the sloW-actingrelay -10, the sidcswitch wiper Vi and its second position contact, the winding of escape magnet 16, to battery and ground. In this instance the escape magnet is arranged to step the side-switch wipers into their third' position upon its energization, and since it is energized through the circuit just described this action will take place. side-switch wiper \V moving into the third )OSlllUll. breaks the encr izin circuit of the" l h h magnet SM, whereby this u'iagnet will be: ronie dct nergized, and the shatt l will be held in its elevated position through the agency of pawl 12.

Let it be assluuod that the first set of contacts encountered in the subgroup G lead to a selective switch which is busy. condition willbe denoted by the absence of ground potential on the test terminal, the esrape magnet 16 will not be energized as before described, and a circuit will be estab- The Such

lished from ground, the contacts 13 operated by the armature of the stepping magnet SM, the winding of relay 10, to battery and ground. Relay 10 being slow to act will not attract its armatures until after sufiicient time has elapsed for the test heretofore described to take place.

Upon the attraction of its armatures by the relay 10, should the first set of termi- I nals in subgroup G lead to an idle selective :circuit previously described, whereby the side-switch wipers will be moved into the third position. In this case, however, the circuit is established from ground, sideswitch wiper I and its third position con tact, the contact and outermost lower armature of the relay 10, the winding of relay 10, to battery and ground. Magnet SM is decnergized as before and the shaft a. is retained in its elevated position through the pawl 12.

The talking conductors of the lines, however, are now extended through ,the two outermost upper armatures and alternate contacts of relay 10 to the brushes of the set I3, the terminals of the subgroup G and then to the seized selected switch. It will be noted that relay 10 is locked in its circuit and will remain so energized until the conclusion of the conversation.

Should the first terminal set in the subgroup G, and the first terminal set of the subgroup Gr have both been found busy, then, upon the energization of relay 10, the circuit for the energization of magnet SM will be opened at the innermost'lower armature and normal contact of relay 10, whereby stepping magnet SM is deenergized. In turn, the circuit for magnet 10 is opened at the contacts 18 which, in retracting its air-- matures, again establishes the circuit for stepping magnet SM, whereupon the shaft 4 is elevated a second step, and the operation of testing, first in the subgroup G and then in .the subgroup G is repeated.

Upon completion of the conversation the seized connector switch is released in the well-known manner, with the result that a ground is placed on the test brush of the selector switch SS and is projected over the innermost upper armature of relay 10, the side-switch wiper W and its third position contact, side-switch Wiper W and its third position contact, the armature and contact of ma et 16, the winding of relay 14 to groun Through the attraction of its armature by relay 1%, the pawls 12 and 15 are withdrawn from their associated ratchet members and the switch is released. A locking circuit for magnet 14 is established from ground, the olf-normal contact ON, the member 15, which serves as an armature of relay 1%, its associated contact, winding of relay lei, to battery, and ground, and this circuit is maintained until the switch is fully restored and the contact ON opened.

IVhat is claimed is: e

1. In a telephone system, a selective switch, groups of circuits terminating therein, means for testing the busy condition of said circuits by groups, means for moving said switch into a plurality of testing positions, and means for successively testing the busy condition of a plurality of circuits in each of said positions.

2. 'In a telephone system, a selective switch, groups of circuits terminating therein. and the combination with means for testing the busy condition of said circuits by groups, of means for successively testing the busy condition of said circuits at a higher speed than the speed of said switch.

3. In a telephone system, a selective switch, groups of fixed terminals, circuits connected thereto, brushes arranged in operative relation to said terminals, motive means for said brushes, testing means responsive to a characteristic electrical condition on said terminals indicating an idle condition of said circuits, said testing means being constructed and arranged to operateat a higher speed than the speed of said switch, and means for determining the busy condition of said circuits by groups before said brushes are sct in motion.

4. In a telephone system, a selective switch, groups of fixed terminals, circuits connected thereto, brushes arranged in operative relation to said terminals, motive means for said brushes, testing means responsive to a characteristic electrical condition on said terminals indicating an idle condition of said circuits, said testing means being constructed and arranged to operate at a higher'speed than the speed of said switch.

5. In a telephone system, a selective switch, groups of fixed terminals, circuits connected thereto, brushes arranged in 115 operative relation to said terminals, testing means responsive to acharacteristic elec trical condition on said terminals indicating an idle condition of said circuits, means for moving said brushes into a plurality of test- 120 ing positions, and means for successively associating said testing means with a plurality of circuits in each of said positions.

6. In a telephone system, a selective switch, groups of, fixed terminals, circuits connected 125 thereto, brushes arranged in operative relation to said terminals, testing means responsive to a characteristic electrical condition on said terminals indicating an idle condition of said circuits, means for moving said 30 All brushes into a plurality of testing positions, means for successively associating said testing means with a plurality of circuits in each. of said positions, and means for determining the busy condition of said circuits by groups before said brushes are set in motion. I

7. In a telephone system, a selective switch, groups; of fixed terminals, circuits connected thereto, means for testing the busy condition of said circuits and groups, means responsive to said testing means for advancing said brushes'to other groups of said terminals, means for moving said brushes into a plurality of testing positions, and means for successively testing the busy condition of 'a plurality of said circuits in each of said positions.

8. In a telephone system, a selective switch, banks of fixed terminals, circuits connected thereto, means for testing said circuits in groups, sets ofbrushesarranged in operative relation to said terminals, actuating means for said brushes, and means fortesting a plurality of said circuits individually during each movement of said brushes.

9. In a telephone system, a selective switch, banks of fixed terminals, circuits connected thereto, sets of brushes arranged in operative relation to said terminals, an auxiliary set of terminals, an auxiliary brush arranged in operativerelation to said auxiliary terminals, means including said auxiliary terminals and said auxiliary brush fortes'ting said circuits in groups, actuating means for said brushes, and means including said terminals and said brushes for testing a plurality of said circuits individually during each movement of said brushes;

10. In a telephone system, a selectiveswitch, banks of fixed terminals, circuits connected thereto; means for testing said circuits in groups, sets of brushes arranged in operative relation to said terminals, means responsive to said group testing means for advancingsaid brushes into association with other banks of said terminals, actuating means for said brushes and means for test ing a pluralityof said circuits individually during each movement of said brushes.

11. In a telephone system, a selective switch, banks of fixed terminals, circuits connected thereto, means for testing said cir cuits in groups, sets of brushes arranged in operative relation to said terminals, means responsive to said group testing means for advancing said brushes into association with other banks of said terminals, actuating means for said brushes, and means for testing a plurality of said circuits individually and in succession during each movement of said brushes.

12. In a telephone system, a selective switch, banks of fixed terminals, circuits con- ,responsive to an electrical condition established through the busy condition of all of the circuits terminating in one bank of said terminals for controlling said actuating means, and means for testing in succession a plurality of said circuits in each operation of said actuating means. 1

13. In a telephone system, a selective switch, banks of terminalssub-divided into groups and subgroups, circuits connected thereto, sets of brushes arranged in operative relation to said terminals in each of said banks of terminals, said sets of brushes being equal innumber to the number of subgroups in each group of said terminals, actuating means for said brushes, testing means responsive to the busy condition of all of the circuits terminating in a group of said terminals for advancing ,saidbrushes into ,association with'another group of said terminals, and means for successively testing an individual circuit in each su'l'igroup of the group with which said brushes have been associated during each movement of said brushes.

1a. In a telephone switching system, switch including a plurality of brushes, a group of circuit terminals, means for simultaneously moving said brushes over said terminals, a test circuit, and means for successively including said brushes separately in said test circuit during the time required to move said brushes between adjacent terminals. i

15. In a telephone switching system, a

switch including a plurality of brushes, a

group of circuit terminals, motive means for simultaneously moving said brushes over said terminals, a test circuit, and switching means cotiperating with said motive means. for separately and successively including said brushes in said test circuit during the time required to move said brushes between adjacent terminals.

16.111 a telephone switching system, a

switch including a plurality of brushes, a'

group of circuit terminals, step-by-ste'p means for simultaneously moving said brushes over said terminals, a test circuit, and means for separately and successively including said brushes in said test circuit during one step of said step-oystep means.

17. in a telephone switching system, a switch including a plurality of brushes, a group of circuit terminals, step-by step means for simultaneously moving said brushes over said terminals, in test circuit, and switching means cofiperating with said step-by-step meansfor separately and suecessively including said brushes in said test circuit lu ing single stepping movement of said switch,-

18. In a telephone switching system, a switch including a plurality of brushes, groups of circuit terminals, means for causing said brushes to automatically move from one group to another in case all of the terminals in the one group test busy, means for simultaneously moving the brushes over the terminals of a group, and means for testing all of the terminals with which said brushes are engaged in any position of the switch.

19. In a telephone switching system, a switch including a plurality r of brushes, groups of circuit terminals, means responsive to directive impulses to move'said brushes into position to engage terminals of one of said groups, means operating automatically in case all terminals of the first group are busy to cause said brushes to move into position to engage terminals of another group, means for simultaneously moving said brushes over the terminals of a group, and means for testing all of the terminals with which said brushes are engaged in any position of the switch] In Witness whereof, We hereunto subscribe our names this 28th day of December A. 1).,

HENRY P. CLAUSEN. CHARLES L. GOODRUM. 

